This invention relates in general to the combustors employed in gas turbine engines and, more particularly, to combustor arrangements with improved combustor fuel flow.
Gas turbine engines typically include annular combustors with a plurality of fuel injectors which are spaced circumferentially around the engine at the combustor section thereof. In one conventional arrangement, each fuel nozzle or injector is coupled via a pressure actuated valve to the fuel supply manifold. In this manner, each injector nozzle is provided with a supply of fuel. Assuming all valve/fuel nozzle combinations are identical and have a common manifold, then they will all have the same fuel flow rate.
To improve ignition, crossfire and altitude relight, it is common to designate one or two of the injectors as "pilot fuel injectors" which have a higher fuel flow rate under all operating conditions, not just at the ignition, crossfire or altitude relight condition. (For purposes of this document, crossfire is defined as the transition from a partially staged combustion to a full burning combustion.) Unfortunately, while the pilot injector approach does provide improved ignition, crossfire and altitude relight, it also produces hot spots or hot streaks within in the combustor section which can cause damage to the combustor section.